[PATCH RT 03/25] sched/deadline: Ensure inactive_timer runs in hardirq context

From: zanussi
Date: Fri Feb 21 2020 - 16:27:01 EST


From: Juri Lelli <juri.lelli@xxxxxxxxxx>

v4.14.170-rt75-rc1 stable review patch.
If anyone has any objections, please let me know.

-----------


[ Upstream commit ba94e7aed7405c58251b1380e6e7d73aa8284b41 ]

SCHED_DEADLINE inactive timer needs to run in hardirq context (as
dl_task_timer already does) on PREEMPT_RT

Change the mode to HRTIMER_MODE_REL_HARD.

[ tglx: Fixed up the start site, so mode debugging works ]

Signed-off-by: Juri Lelli <juri.lelli@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190731103715.4047-1-juri.lelli@xxxxxxxxxx
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
kernel/sched/deadline.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index eb68f7fb8a36..7b04e54bea01 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -252,7 +252,7 @@ static void task_non_contending(struct task_struct *p)

dl_se->dl_non_contending = 1;
get_task_struct(p);
- hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL);
+ hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL_HARD);
}

static void task_contending(struct sched_dl_entity *dl_se, int flags)
@@ -1234,7 +1234,7 @@ void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se)
{
struct hrtimer *timer = &dl_se->inactive_timer;

- hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
timer->function = inactive_task_timer;
}

--
2.14.1